The present invention deals with position indicator systems for operator setable control elements such as those employed in power drive systems, e.g. vehicle drive systems. In such environments, the position of operator setable control elements provided drive system control functions, for example, control over fuel adjusting elements and coupling devices.
Among generally known position indicators were contact type on/off switches, (e.g. Micro-switches), potentiometers and Hall generators. One of the disadvantages of contact type on/off switches when employed as position indicators was that they could not generate a continuously variable signal because they switched only upon sensing certain positions of monitored movement. Further, contact type switches were susceptible to mechanical wear and therefore, reliability after extended operation suffered.
The employment of potentiometers as position indicators did permit the generation of a continuously variable signal for measurement of the position of a monitored element but, they too had limited useful life due to friction and wear between components.